1. Field of the Invention
The invention relates to hydrophilic organofunctional silicone copolymers, a process for the preparation thereof and the use thereof.
2. Description of the Related Art
Hydrophilic organofunctional silicone copolymers are silicone polyethers, i.e. polysiloxanes modified with polyalkylene oxides. Such products are used in cosmetics as dimethicone copolyols, as a protective colloid and emulsifier, as an antifoam or in the finishing of textiles as hydrophilic softeners.
The prior art to date regarding the preparation of such compounds is to subject H-siloxanes to hydrosilylation with unsaturated polyethers (polyalkylene oxides). The presence of a platinum catalyst is required for this purpose, which, however, introduces heavy metals into the end product. A further disadvantage of this reaction is the insufficient linkage of the unsaturated polyether to the silicone chain, so that free polyether is still present in the product even after the reaction. The linkage is to some extent satisfactorily possible only when the unsaturated polyether has allyl groups, but this results in undesired rearrangement reactions and in the formation of byproducts. It is therefore generally necessary to employ an excess of allylpolyether. Vinyl or (meth)acryloyl groups lead to even poorer linkage. In the case of acryloyl or methacryloyl functions, 1,4-addition and the formation of an unstable Si—O—C bond, i.e. a very labile and virtually unstable linkage, very frequently results. These insufficient linkages can lead to inhomogeneities of the product, e.g. phase separation, and to negative properties during the use thereof.
DE 10020670 A1 describes organosiloxanyl derivatives which have been modified with polyalkylene glycol and are obtained by means of hydrosilylation of H-siloxanes with a vinyl-functional polyalkylene oxide. EP 1097701 A1 and EP 1284282 A1 disclose polyoxyalkylene-polysiloxane copolymers which are obtained by means of hydrosilylation of H-siloxanes with unsaturated polyethers in the presence of a metal catalyst and are used as an emulsifier or antifoam. WO 99/10412 A1 relates to polysiloxane-polyalkylene oxide block copolymers which are obtainable by means of hydrosilylation. WO 02/15853 A1 describes the use of vinyl ester copolymers in cosmetic hair formulations, the polymerization of the vinyl ester being effected in the presence of polyether-containing compounds which may contain silicone moieties. JP 2000-044639 relates to the preparation of aqueous synthetic resin emulsions for coating materials and adhesives, ethylenically unsaturated monomers being polymerized in an aqueous medium in the presence of a macromonomer which is obtained by reaction of a silicone having a terminal unsaturated group and a polyalkylene glycol (meth) acrylate.